A Quasi-Macroscopic Approach for Examining the Vibrational Behaviour of Gasdynamic Lasing Molecules
M.A. Grado-Caffaro and M. Grado-Caffaro
A theoretical-analytical investigation on the vibrational behaviour of gasdynamic lasing molecules is carried out. In fact, the Morse potential is regarded to act over the inter-nuclear axis of the molecules which, as a result, behave as quantum anharmonic oscillators. Although our formulation is centered on diatomic molecules (consider, for example, carbon-monoxide molecules), it is well-known that, by virtue of the united-atom approximation, the Morse potential is also suitable to describe the vibrational behaviour of certain polyatomic molecules as, for instance, carbon-dioxide molecules. In the present article, we establish a quasi-macroscopic (or mesoscopic) model to determine the (minimum) center of mass velocity of a diatomic molecule relative to a gasdynamic laser. More precisely, we determine the above velocity for relatively large quantum vibrational states belonging to the finite set of bound quantum states due to the Morse potential. We show that this situation, although far from the classical limit, may be viewed as quasi-macroscopic or mesoscopic.
Keywords: Gasdynamic laser; Lasing molecules; Morse potential; Quasi-macroscopic approximation; Molecule velocity